Split root system for the use of saline water in hydroponic tomato production

Tomato plants (Lycopersicon esculentum Mill. var. DRK) were grown with split root system to determine the effect of an unequal distribution of salinity in the root zone on yield and blossom end rot (BER). The roots of the plant were divided into two portions and each portion was irrigated with nutrient solutions differing in EC levels achieved by adding Na or all nutrients proportionally. The maximum yield was achieved in treatments with unequal EC when one portion of the roots received only water and the lowest in the high EC treatments. The reduced yield in the high EC treatment was due to the incidence of BER and reduced fruit size. In treatments with unequal salt distribution, the main source of water was from that portion of the root system in the least saline zone. The concentration of Na in the leaves and fruit was reduced significantly where one portion of the root system was supplied with water. Solutions with high EC supplied to both sides of the root system significantly increased the incidence of BER, but when only water or a solution with low EC was supplied to one side, BER was reduced by 70%. Ca concentration in the distal end of fruits was significantly higher in the treatments where one portion of the root system received water. It was concluded that high salinity had positive effects on yield and quality provided that one portion of the root system is placed in low EC or water only.